Valve with Operating Means Between Two Outlet Passages

ABSTRACT

A valve has a body, a fluid inlet duct delimited by the body, two fluid outlet ducts into which the fluid inlet duct opens, an intersection formed by the two fluid outlet ducts, a butterfly valve disposed in the intersection, and a motor, to which the butterfly valve is connected, for actuating the butterfly valve between a first extreme position in which the butterfly valve directs the fluid mainly toward the first outlet duct and a second extreme position in which the butterfly valve directs the fluid mainly toward the second outlet duct. The motor is placed between the outlet ducts in the vicinity of a connecting zone connecting the two outlet ducts to one another. The butterfly valve is mounted in front of the connecting zone so that the butterfly valve forms a screen against the fluid for the connecting zone.

The present invention relates to a valve that can be used for example ina device for recirculating the exhaust gases of a motor vehicle internalcombustion engine.

BACKGROUND OF THE INVENTION

An Exhaust Gas Recirculation device (or EGR) usually comprises a cooledchannel and an uncooled channel connected on the one hand to the inletcircuit of the internal combustion engine and on the other hand to atapping made in the high pressure zone of the exhaust manifold of theinternal combustion engine. The two channels are connected to oneanother by a valve, called the “by-pass valve”, that regulates the flowof the exhaust gases between the cooled channel and the uncooledchannel. Such a recirculation device allows a portion of the exhaustgases to be reutilized in the mixture fed into the internal combustionengine.

From now onwards, the antipollution standards make it necessary torecirculate a larger portion of the exhaust gases. The currentarchitecture has reached its limits with respect to the quantity ofexhaust gas that it is possible to recirculate.

To improve the recirculation of the exhaust gases, thought has beengiven to connecting a recirculation device to the low pressure portionof the exhaust manifold, that is to say downstream of the exhaust gasexpansion zone, in order to direct the majority of the exhaust gasestoward the internal combustion engine inlet circuit. It is thereforenecessary to provide a valve on the low pressure portion of the exhaustmanifold making it possible to direct the exhaust gases either towardthe outside or toward the recirculation device. However, in this portionof the manifold, the exhaust gases undergo depollution treatments,particularly a post-combustion, that raise their temperature.

The valve must be arranged to withstand this temperature, whichincreases the cost of the valve and more particularly that of themembers controlling the latter such as the actuation motor and the meansof transmitting the movement from the motor to the butterfly valve. Onesolution would be to distance the control members as much as possiblefrom the ducts in which the hot exhaust gases travel. However, it is, onthe contrary, desirable for the valve to have a structure that iscompact and neatly arranged on the exhaust manifold in order to limitthe space requirement. Such a structure promotes a high temperature ofthe valve and makes it difficult to cool.

OBJECT OF THE INVENTION

One object of the invention is to propose a valve satisfying the aboverequirements.

BRIEF DESCRIPTION OF THE INVENTION

For this reason, according to the invention, a valve is providedcomprising a body delimiting a fluid inlet duct opening into two fluidoutlet ducts forming an intersection in which a butterfly valve ismounted connected to a motor for actuating the butterfly valve between afirst extreme position in which the butterfly valve directs the fluidmainly toward the first outlet duct and a second extreme position inwhich the butterfly valve directs the fluid mainly toward the secondoutlet duct, the motor being placed between the outlet ducts in thevicinity of a zone connecting the outlet ducts to one another and thebutterfly valve being mounted in front of the connecting zone so thatthe butterfly valve forms a screen against the fluid for this connectingzone.

Therefore, the position of the motor between the outlet ducts in thevicinity of the connection of the latter makes it possible to obtain acompact structure around the outlet ducts. The butterfly valve, byforming a screen, prevents the connecting zone from being in directcontact with the fluid transported and in this way limits the influenceof the temperature of the fluid on that of the motor.

Preferably, the motor is contained in a housing having a wall formingthe connecting zone of the outlet ducts.

The compactness of the valve is therefore further enhanced.

According to a particular embodiment, the housing is provided with meansfor cooling the wall forming the connecting zone.

The cooling means make it possible to keep the motor and the means fortransmitting the movement to the butterfly valve at an optimaltemperature. In addition, these cooling means make it possible to userelatively common elastomer sealing elements instead of elastomerelements made of a high heat-resistant material. These sealing elementsprovide a satisfactory seal for a relatively low cost.

Advantageously, the butterfly valve has at least one portion extendingalong at least one portion of the wall of the housing when the butterflyvalve is in its extreme positions.

The butterfly valve may then be subjected at least in part to the actionof the cooling means directly by conduction or at least indirectly. Thisalso limits the risk that the transported fluid circulates between thebutterfly valve and the wall.

Again preferably, the butterfly valve is supported by a spindle havingends received in bearings subjected to the cooling means.

The cooling of the bearings limits the risk of the latter seizing andallows cooling by conduction of the spindle and of the butterfly valve.

Again advantageously, the butterfly valve is supported by a spindleextending in the immediate vicinity of the wall along a portion of thelatter.

Cooling of the spindle by radiation is therefore possible.

Other features and advantages of the invention will emerge on readingthe following description of a particular nonlimiting embodiment of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will be made to the appended drawings, amongst which:

FIG. 1 is a view in perspective of the valve according to the inventionwith cutaway,

FIG. 2 is a schematic top view of this valve, in section along the planeII of FIG. 1, for a first position of the butterfly valve,

FIG. 3 is a view similar to FIG. 2 for a second position of thebutterfly valve.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the figures, the valve generally indicated byreference number 1 is here designed to be placed on the low pressureportion of the exhaust manifold 100 of an internal combustion engine inorder to direct the exhaust gases either toward the outside or toward arecirculation device 101 (only one portion of the inlet duct of therecirculation device is shown). Taking as an example an internalcombustion engine fitted with a turbocharger, the low pressure portionof the exhaust manifold is downstream of the turbocharger turbine.

The valve 1 comprises a body 2 delimiting an inlet duct 3 opening intotwo outlet ducts 4, 5 forming an intersection 6. The inlet duct 3 hasone end provided with means for connecting it to the exhaust manifold100 on the internal combustion engine side and an opposite end connectedto first convergent ends of two outlet ducts 4, 5 having opposite endsprovided with means for connecting them respectively to therecirculation device 101 and to the final section 102 of the exhaustmanifold 100. The first ends of the outlet ducts 4, 5 are connectedsubstantially forming a right angle whose apex is oriented toward theinlet duct 3.

The internal portion of the right angle is formed by a wall 7 of ahousing 8 connecting the outlet ducts 4, 5 in the internal portion ofthe right angle. The wall 7 therefore forms a zone for connecting theoutlet ducts 4, 5. The housing 8 is formed of an aluminum casingincorporating means for cooling it more particularly providing thecooling of the wall 7. These cooling means comprise in this instance achannel having an inlet portion 13 and an outlet portion 14 made in thecasing forming the housing 8 in order to allow the circulation of aheat-conducting fluid. The portions 13 and 14 of the cooling channel arein this instance designed to be connected to the cooling circuit of theinternal combustion engine.

The housing 8 accommodates a motor 9 for actuating a butterfly valve 10mounted in the intersection 6 upstream of the wall 7 with reference to adirection of flow of the exhaust gases in the ducts 3, 4, 5. The motor 9is a direct current electric motor. The butterfly valve 10 is fixedlyattached to a spindle 11 that extends in the immediate vicinity andalong the wall 7 and that has ends received pivotingly in bearings 12fixedly attached to the housing 8 so that the bearings 12 benefit atleast in part from the cooling provided to the wall 7 by the coolingchannel of the housing 8. The cooling channel has its inlet portion 13and outlet portion 14 that are adjacent to the bearings 12 and incontact with the latter in order to cool said bearings 12. The closenessof the spindle 11 to the wall 7 promotes the cooling of the spindle 11.Preferably the cooling channel passes close to the spindle 11. Thespindle 11 is connected to the output shaft of the motor 9 bytransmission means of conventional type, in this instance gears 15mounted on the housing 8 so as to be subjected to the action of thecooling means of the housing 8. The gears 15 are in this instance madeof plastic. Beneath the gears, a seal (not visible in the figures) isplaced on the spindle 11 in order to form a seal between the spindle 11and the body 2. The cooling of the spindle 11 allows the use of anelastomer seal. The same applies to the other sealing elements of thevalve being able to benefit directly or indirectly from the coolingprovided by the cooling means. The sealing elements subjected to highertemperature are made of a highly heat-resistant material such as aceramic.

The butterfly valve 10 can therefore be moved between a first extremeposition in which the butterfly valve 10 directs the fluid mainly towardthe outlet duct 4 and a second extreme position in which the butterflyvalve 10 directs the fluid mainly toward the outlet duct 5.

In its first extreme position, the butterfly valve 10 has a portion 10.1extending along the wall 7 on the side of the outlet duct 4 and aportion 10.2 partially blocking the outlet duct 5. The portion 10.1 hasa free edge resting against the wall 7. A recess 16 of the wall 7 formsa thin free space left behind the portion 10.1.

In its second extreme position, the butterfly valve 10 has its portion10.2 extending along the wall 7 on the side of the outlet duct 5 and itsportion 10.1 blocking the outlet duct 4. The portion 10.2 has a freeedge resting against the wall 7. A recess 17 of the wall 7 forms a thinfree space left behind the portion 10.2. The operation and the controlof this valve are conventional.

Naturally, the invention is not limited to the embodiment described butcovers any variant included in the context of the invention defined bythe claims.

In particular, although the valve of the invention has been described inan application to the recirculation of the exhaust gases, the valve maybe used in other applications for regulation or distribution of fluidsand particularly for fluids of lower temperatures.

In addition, the housing 8 may be placed in the vicinity of theconnecting zone without said connecting zone being formed by a wall ofthe housing 8. The increase in the space requirement resulting from thispositioning of the housing is compensated for by the fact that, by beingat a slight distance from the connecting zone, the motor naturally has alower temperature, which makes it easier to cool. The housing 8 maytherefore be separated from the ducts.

Although it has been indicated that the housing of the motor is made ofaluminum and the gears of plastic (which makes it possible to have arelatively light valve), it is possible to make these elements of steel.

The body 2 may also be made in one or more parts.

1. A valve comprising: a body; a fluid inlet duct delimited by the body;two fluid outlet ducts into which the fluid inlet duct opens; anintersection formed by the two fluid outlet ducts; a butterfly valvedisposed in the intersection; and a motor, to which the butterfly valveis connected, for actuating the butterfly valve between a first extremeposition in which the butterfly valve directs the fluid mainly towardthe first outlet duct and a second extreme position in which thebutterfly valve directs the fluid mainly toward the second outlet duct,wherein the motor is placed between the outlet ducts in the vicinity ofa connecting zone connecting the two outlet ducts to one another, andwherein the butterfly valve is mounted in front of the connecting zoneso that the butterfly valve forms a screen against the fluid for theconnecting zone.
 2. The valve as claimed in claim 1, wherein the motoris contained in a housing having a wall forming the connecting zone ofthe outlet ducts.
 3. The valve as claimed in claim 2, wherein thehousing is provided with cooling means for cooling the wall forming theconnecting zone.
 4. The valve as claimed in claim 3, wherein thebutterfly valve has at least one portion extending along at least oneportion of the wall of the housing when the butterfly valve is in theextreme positions.
 5. The valve as claimed in claim 3, wherein thebutterfly valve is supported by a spindle having ends received inbearings fixedly attached to the housing and subjected to the coolingmeans.
 6. The valve as claimed in claim 3, wherein the butterfly valveis supported by a spindle extending in the immediate vicinity of thewall along a portion of the latter.